Diversity of genetic lineages among CTX-M-15 and CTX-M-14 producing Escherichia coli strains in a Tunisian hospital

  1. Ben Slama, K. 3
  2. Ben Sallem, R. 3
  3. Jouini, A. 3
  4. Rachid, S. 3
  5. Moussa, L. 4
  6. Sáenz, Y. 2
  7. Estepa, V. 1
  8. Somalo, S. 1
  9. Boudabous, A. 3
  10. Torres, C. 12
  1. 1 Universidad de La Rioja
    info

    Universidad de La Rioja

    Logroño, España

    ROR https://ror.org/0553yr311

  2. 2 Centro de Investigación Biomédica de La Rioja
    info

    Centro de Investigación Biomédica de La Rioja

    Logroño, España

    ROR https://ror.org/03vfjzd38

  3. 3 Université de Tunis El Manar
    info

    Université de Tunis El Manar

    Túnez, Túnez

    ROR https://ror.org/029cgt552

  4. 4 Laboratoire de Microbiologie, Polyclinique Ettaoufik, Tunis, Tunisia
Mostrar afiliaciones +
Revista:
Current Microbiology

ISSN: 0343-8651

Año de publicación: 2011

Volumen: 62

Número: 6

Páginas: 1794-1801

Tipo: Artículo

DOI: 10.1007/S00284-011-9930-4 PMID: 21479796 SCOPUS: 2-s2.0-79958276950 WoS: WOS:000292561100021 GOOGLE SCHOLAR

Otras publicaciones en: Current Microbiology

Resumen

Fourteen broad-spectrum-cephalosporin-resistant Escherichia coli isolates were recovered between June and December 2007 in a Tunisian hospital. Genes encoding extended-spectrum-beta-lactamases (ESBL) and other resistance genes were characterized by PCR and sequencing. The following ESBL genes were identified: bla CTX-M-15 (12 isolates), bla CTX-M-14a (one isolate), and bla CTX-M-14b (one isolate). The bla OXA-1 gene was detected in 13 bla CTX-M-producing strains and a bla TEM-1 gene in 6 of them. The ISEcp1 sequence was found upstream of bla CTX-M genes in 8 of 14 strains, and orf477 or IS903 downstream of this gene in 13 strains. Nine of the strains carried class 1 integrons and five different gene cassette arrangements were detected, dfrA17-aadA5 being the most common. One of the strains (bla CTX-M-14a-positive) harbored three class 1 integrons, and one of them was non-previously described containing as gene cassettes new variants of aac(6′)-Ib and cmlA1 genes and it was linked to the bla CTX-M-14a gene flanked by a truncated ISEcp1 sequence (included in GenBank with accession number JF701188). CTX-M-15-producing strains were ascribed to phylogroup B2 (six isolates) and D (six isolates). Multilocus-sequence-typing revealed ten different sequence-types (STs) among ESBL-positive E. coli strains with prevalence of ST405 (four strains of phylogroup D) and ST131 types (two strains of phylogroup B2 and serogroup O25b). A high clonal diversity was also observed among studied strains by pulsed-field-gel-electrophoresis (11 unrelated profiles). CTX-M-15 is an emergent mechanism of resistance in the studied hospital and the world-disseminated 0:25b-ST131-B2 and ST405-D clones have been identified among CTX-M-15-producing isolates. © 2011 Springer Science+Business Media, LLC.